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United States Patent |
6,254,087
|
Johdai
,   et al.
|
July 3, 2001
|
Sheet transport device and sheet transport method
Abstract
According to a document transport device of a preferred embodiment, when
reading images of a plurality of one-sided documents, these one-sided
documents are accommodated in a first accommodating portion with the
document surface facing upward. The held documents are fed sequentially
from the uppermost document to the first document transport path, inverted
front-to-back, and transported with the document surface facing downward
to the predetermined position, i.e., the document reading position. When
the reading of the document is completed at the document reading position,
the read document is transported to a second document transport path,
inverted front-to-back, and accommodated in a second accommodating portion
with the document surface facing upward. Thereafter, the document is
transported to a third document transport path, inverted front-to-back,
and accommodated in a third document accommodating portion with the
document surface facing downward. The second and subsequent documents are
similarly transported, and stacked in the third accommodating portion with
the document surfaces facing downward.
Inventors:
|
Johdai; Akiyoshi (Toyokawa, JP);
Murakami; Tohru (Okazaki, JP)
|
Assignee:
|
Minolta Co., Ltd. (Osaka, JP)
|
Appl. No.:
|
407175 |
Filed:
|
September 28, 1999 |
Foreign Application Priority Data
| Sep 30, 1998[JP] | 10-277582 |
Current U.S. Class: |
271/184; 271/186; 399/364 |
Intern'l Class: |
B65H 029/00; G03G 015/00 |
Field of Search: |
271/4.09,184,186
399/364
|
References Cited
U.S. Patent Documents
4849790 | Jul., 1989 | Ito | 355/321.
|
4921239 | May., 1990 | Okui et al. | 271/186.
|
5197724 | Mar., 1993 | Kitijama et al. | 271/3.
|
5534989 | Jul., 1996 | Rubscha et al. | 355/309.
|
5597153 | Jan., 1997 | Maruyama et al. | 271/4.
|
5784680 | Jun., 1998 | Taruki | 399/374.
|
6029969 | Feb., 2000 | Saitoh et al. | 271/4.
|
Foreign Patent Documents |
4-28677 | Jan., 1992 | JP.
| |
4-255866 | Sep., 1992 | JP.
| |
5-249780 | Sep., 1993 | JP.
| |
5-338892 | Dec., 1993 | JP.
| |
Primary Examiner: Ellis; Christopher P.
Assistant Examiner: Bower; Kenneth W
Attorney, Agent or Firm: Burns, Doane, Swecker & Mathis, LLP
Claims
What is claimed is:
1. A sheet transport device for transporting sheet to a predetermined
position, said sheet transport device comprising:
a first accommodating portion which is disposed above the predetermined
position and which accommodates a plurality of sheets;
a second accommodating portion disposed above the predetermined position;
a third accommodating portion disposed above the predetermined position;
a first sheet transport path for feeding the plurality of sheets
accommodated in said first accommodating portion sequentially from the
uppermost sheet, inverting the sheets front-to-back, and transporting the
sheets to the predetermined position;
a second sheet transport path for inverting front-to-back the sheet which
is transported to the predetermined position by said first transport path,
and transporting the sheet to said second accommodating portion; and
a third sheet transport path for inverting front-to-back the sheet which is
accommodated by said second accommodating portion, and transporting the
sheet to said third accommodating portion.
2. A sheet transport device as claimed in claim 1, wherein said third
accommodating portion is positioned above said second accommodating
portion, and said first accommodating portion is positioned above said
third accommodating portion.
3. A sheet transport device as claimed in claim 1, wherein said sheet
transporting apparatus is attachable to an image processing apparatus, and
said predetermined position corresponds to an image reading position of
the image processing apparatus when the sheet transport device is attached
to the image processing apparatus.
4. A sheet transport device for transporting sheet to a predetermined
position, said sheet transport device comprising:
a first accommodating portion which is disposed above the predetermined
position and which accommodates a plurality of sheets;
a second accommodating portion disposed above the predetermined position;
a third accommodating portion disposed above the predetermined position;
a fourth accommodating portion disposed above the predetermined position;
a first sheet transport path for feeding the plurality of sheets
accommodated in said first accommodating portion sequentially from the
lowermost sheet, inverting the sheet front-to-back, and transporting the
sheet to said second accommodating portion;
a second sheet transport path for inverting front-to-back a sheet which is
accommodated in said second accommodating portion, and transporting the
sheet to the predetermined position;
a third sheet transport path for inverting front-to-back the sheet which is
transported to the predetermined position by said second transport path,
and transporting the sheet to said third accommodating portion; and
a fourth sheet transport path for inverting front-to-back the sheet
accommodated in said third accommodating portion, and transporting the
sheet to the fourth accommodating portion.
5. A sheet transport device as claimed in claim 3, wherein said second
accommodating portion is positioned above said third accommodating
portion, said forth accommodating portion is positioned above said second
accommodating portion, and said first accommodating portion is positioned
above said fourth accommodating portion.
6. A sheet transport device as claimed in claim 3, wherein said sheet
transporting apparatus is attachable to an image processing apparatus, and
said predetermined position corresponds to an image reading position of
the image processing apparatus when the sheet transport device is attached
to the image processing apparatus.
7. A sheet transporting method for transporting sheet to a predetermined
position, said sheet transporting method comprising steps of:
feeding a plurality of sheets accommodated in a first accommodating portion
sequentially from the uppermost sheet, said first accommodating portion
being disposed above the predetermined position;
inverting said fed sheets front-to-back, and transporting the sheets to the
predetermined position;
inverting front-to-back the sheet transported to the predetermined
position, and transporting the sheet to a second accommodating portion,
said second accommodating portion being disposed above the predetermined
position; and
inverting front-to-back the sheet accommodated in said second accommodating
portion, and transporting the sheet to a third accommodating portion, said
third accommodating portion being disposed above the predetermined
position.
8. A sheet transporting method as claimed in claim 7, wherein said third
accommodating portion is positioned above said second accommodating
portion, and said first accommodating portion is positioned above said
third accommodating portion.
9. A sheet transporting method as claimed in claim 7, wherein said sheet
transporting method is used in an image processing apparatus, and said
predetermined position corresponds to an image reading position of the
image processing apparatus.
10. A sheet transporting method for transporting sheet to a predetermined
position, said sheet transporting method comprising steps of:
feeding a plurality of sheets accommodated in a first accommodating portion
sequentially from the lowermost sheet, a first accommodating portion being
disposed above the predetermined position;
inverting said fed sheet front-to-back, and transporting the sheet to the
second accommodating portion, said second accommodating portion being
disposed above the predetermined position;
inverting front-to-back the sheet accommodated by said second accommodating
portion, and transporting the sheet to the predetermined position;
inverting front-to-back the sheet which is transported to the predetermined
position, and transporting the sheet to a third accommodating portion,
said third accommodating portion being disposed above the predetermined
position; and
inverting front-to-back the sheet accommodated in said third accommodating
portion, and transporting the sheet to a fourth accommodating portion,
said fourth accommodating portion being disposed above the predetermined
position.
11. A sheet transporting method as claimed in claim 10, wherein said second
accommodating portion is positioned above said third accommodating
portion, said forth accommodating portion is positioned above said second
accommodating portion, and said first accommodating portion is positioned
above said fourth accommodating portion.
12. A sheet transporting method as claimed in claim 10, wherein said sheet
transporting method used in an image processing apparatus, and said
predetermined position corresponds to an image reading position of the
image processing apparatus when the sheet transport device is attached to
the image processing apparatus.
Description
This application is based on Patent Application No. H10-277582 filed in
Japan, the content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sheet transport device and sheet
transport method for use in image forming apparatuses such as copiers,
scanners, facsimile machine and the like.
2. Description of the Related Art
Document transport devices installed in image processing apparatuses having
both a document feeding tray and a document discharge tray disposed above
the platen of the image reading unit of the image processing apparatus are
hereinafter referred to as "wingless-type document transport devices."
Furthermore, document transport devices having at least one tray among the
document feeding tray and the document discharge tray which protrudes from
the area above the platen are hereinafter referred to as "wing-type
document transport devices." The wingless-type document transport device
is advantageous in that it has a smaller footprint so as to more
effectively utilize space compared to the wing-type document transport
device.
Document transport systems can be classified from the perspective of the
document feeding sequence into "first page systems" wherein a plurality of
document pages are fed from the first page, and "last page systems"
wherein the last page of the plurality of document pages is fed first.
When comparing the first page system and the last page system, there is no
problem using either system in copiers which simply make copies, but the
first page system is desirable in apparatuses which process read
information in the reading sequence as is the case in scanners and
facsimile machines.
The wingless-type document transport devices invert front-to-back a
document placed on the document feed tray and feed the document to the
image reader unit, then again invert the document back-to-front after the
image is read and eject the document to a document discharge tray.
Accordingly, disadvantages arise when using the first page system.
Specifically, when automatically reading a plurality of one-sided
documents, the plurality of one-sided documents are stacked on a document
tray with the document surface facing upward, and the uppermost document
is fed sequentially from the first page. The documents which have been
read are sequentially ejected to the document discharge tray with the
document surface face upward. As a result the first page document becomes
the lowermost document in the stack with the document surface facing
upward. For this reason the operator must re-order the sequence of the
documents after the documents have been read.
OBJECTS AND SUMMARY
In view of the aforesaid disadvantages, an object of the present invention
is to provide an improved sheet transport device and sheet transporting
method.
Another object of the present invention is to provide a sheet transport
device and sheet transporting method which do not require reordering of
the sequence of sheets ejected to a sheet discharge tray.
Yet another object of the present invention is to provide a sheet transport
device and sheet transporting method having excellent operating
characteristics using the first page system in wingless-type sheet
transport devices.
These and other objects of the present invention are attained by providing
a sheet transport device for transporting sheets to a predetermined
position, said sheet transport device comprising:
a first accommodating portion which is disposed above the predetermined
position and which accommodates a plurality of sheets;
a second accommodating portion disposed above the predetermined position;
a third accommodating portion disposed above the predetermined position;
a first sheet transport path for feeding the plurality of sheets
accommodated in said first accommodating portion sequentially from the
uppermost sheet, inverting the sheets front-to-back, and transporting the
sheets to the predetermined position;
a second sheet transport path for inverting front-to-back the sheet which
is transported to the predetermined position by said first transport path,
and transporting the sheet to said second accommodating portion; and
a third sheet transport path for inverting front-to-back the sheet which is
accommodated by said second accommodating portion, and transporting the
sheet to said third accommodating portion.
According to this sheet transport device, when reading the images of a
plurality of one-sided documents, these one-sided documents are
accommodated in a first accommodating portion with the document surface
facing upward. The held documents are fed sequentially from the uppermost
document to the first document transport path, inverted front-to-back, and
transported with the document surface facing downward to the predetermined
position, i.e., the document reading position. When the reading of the
document is completed at the document reading position, the read document
is transported to the second document transport path, inverted
front-to-back, and accommodated in the second accommodating portion with
the document surface facing upward. Thereafter, the document is
transported to the third document transport path, inverted front-to-back,
and accommodated in the third accommodating portion with the document
surface facing downward. The second and subsequent documents are similarly
transported, and stacked in the third accommodating portion with the
document surfaces facing downward.
These objects of the present invention are attained by providing a sheet
transport device for transporting sheets to a predetermined position, said
sheet transport device comprising:
a first accommodating portion which is disposed above the predetermined
position and which accommodates a plurality of sheets;
a second accommodating portion disposed above the predetermined position;
a third accommodating portion disposed above the predetermined position;
a fourth accommodating portion disposed above the predetermined position;
a first sheet transport path for feeding the plurality of sheets
accommodated in said first accommodating portion sequentially from the
lowermost sheet, inverting the sheet front-to-back, and transporting the
sheet to said second accommodating portion;
a second sheet transport path for inverting front-to-back a sheet which is
accommodated in said second accommodating portion, and transporting the
sheet to the predetermined position;
a third sheet transport path for inverting front-to-back the sheet which is
transported to the predetermined position by said second transport path,
and transporting the sheet to said third accommodating portion; and
a fourth sheet transport path for inverting front-to-back the sheet
accommodated in said third accommodating portion, and transporting the
sheet to the fourth accommodating portion.
According to this sheet transport device, when reading the images of a
plurality of one-sided documents, these one-sided documents are
accommodated in a first accommodating portion with the document surface
facing downward. The accommodated documents are fed sequentially from the
lowermost document via the first document transport path, inverted
front-to-back, and accommodated with the document surface facing upward in
the second accommodating portion. The document in the second accommodating
portion is transported via the second document transport path, inverted
front-to-back, and transported with the document surface facing downward
to the predetermined position, i.e., the document reading position. When
the reading of the document is completed at the document reading position,
the read document is transported via the third document transport path,
inverted front-to-back, and accommodated in the third accommodating
portion with the document surface facing upward. Thereafter, the document
in the third accommodating portion is transported via the fourth document
transport path, inverted front-to-back, and accommodated in the fourth
accommodating portion with the document surface facing downward. The
second and subsequent documents are similarly transported, and stacked in
the fourth accommodating portion with the document surfaces facing
downward.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the present invention will become
apparent from the following description of the preferred embodiments
thereof taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a conceptual drawing showing a first mode of the document
transport device;
FIG. 2 is a conceptual drawing showing a second mode of the document
transport device; and
FIG. 3 is a section view showing the construction of the document transport
device.
In the following description, like parts are designated by like reference
numbers throughout the several drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a conceptual drawing showing a first mode of the document
transport device. The document transport device 10 is arranged above the
platen 14 of the document reading unit of the image forming apparatus 12,
e.g., a copier, scanner, facsimile machine or the like. In this
arrangement, above the platen 14 are arranged a first document holder 16,
a second document holder 18, and a third document holder 20. Sequentially
from the top are disposed the first document holder 16, the third document
holder 20, and the second document holder 18. The document transport
device 10 is provided with a first document transport path 22 for
inverting front-to-back the documents from the first document holder 16
and transporting them to the document reader 14, a second document
transport path 22 for inverting front-to-back the documents from the
document reader 14 and transporting them to the second document holder 18,
and a third document transport path 26 for inverting front-to-back the
documents from the second document holder 18 and transporting them to the
third document holder 20.
When reading a one-sided document P, the document feeder 10 accommodates a
plurality of document pages P stacked in the page sequence in the first
document holder 16 with the document surface facing upward. The plurality
of documents P are stacked in the first document holder 16 with the first
page document surface facing upward. The documents held in the first
document holder 16 are fed sequentially from the uppermost document, i.e.,
the first page, to the first document transport path 22. A fed document P
is inverted front-to-back by being transported along the first transport
path 22, so as to arrive at the document reader 14 with the document
surface facing downward. When document reading ends by the document
processing device 12, the document P is fed from the document reader 14 to
the second document transport path 24. The fed document P is transported
along the second transport path 24, inverted front-to-back, and
transported to the second document holder 18. Thereafter, the document P
is transported from the second document holder 18 along the third document
transport path 26, inverted front-to-back, so as to be accommodated in the
third document holder 20 with the document surface facing downward.
FIG. 2 shows a second mode of the document transport device. The document
transport device 30 provides a first document holder 36, a second document
holder 38, a third document holder 40, and a fourth document holder 42
arranged above the document reader 34 of the image processing device 32.
Sequentially from the top are disposed the first document holder 36, the
fourth document holder 42, the second document holder 38, and the third
document holder 40. The document transport device 30 is provided with a
first document transport path 44 for inverting front-to-back the documents
from the first document holder 36 and transporting them to the second
document holder 38, a second document transport path 46 for inverting
front-to-back the documents accommodated in the second document holder 38
and transporting them to the document reader 34, a third document
transport path 48 for inverting front-to-back the documents from the
document reader 34 and transporting them to the third document holder 40,
and a fourth document transport path 50 for inverting front-to-back the
documents accommodated in the third document holder 40 and transporting
them to the fourth document holder 42.
When reading a one-sided document P, the document feeder 30 accommodates a
plurality of document pages P stacked in the page sequence in the first
document holder 36 with the document surface facing downward. The
plurality of documents P are stacked in the first document holder 36 with
the first page document surface facing downward. The documents held in the
first document holder 36 are fed sequentially from the lowermost document,
i.e., the first page, to the first document transport path 44. A fed
document P is inverted front-to-back by being transported along the first
transport path 44, so as to be accommodated in the second document holder
38 with the document surface facing upward. Then, the document P is
inverted front-to-back by being transported from the second document
holder 38 via the second transport path 46, so as to arrive at the
document reader 34 with the document surface facing downward. When
document reading ends by the document processing device 32, the document P
is fed from the document reader 34 and inverted front-to-back by the third
transport path 48, and is accommodated in the third document holder 40.
Thereafter, the document P is transported from the third document holder
40 along the fourth document transport path 50, and inverted
front-to-back, so as to be accommodated in the fourth document holder 42
with the document surface facing downward.
FIG. 3 is a section view of the document transport device 100 of the first
mode described above. The document transport device 100 is arranged above
the platen of a document reader 104 of an idealized image processing
device, e.g., a copier, facsimile, or scanner 102. The document transport
device 100 is connected to the image processing apparatus so as to be
freely oscillatable via a hinge provided on the interior side in the
drawing, so as to allow the platen 104 to be opened as necessary.
The document transport device 100, in brief, has an approximately
rectangular box-like housing, and is provided with a document feed tray
108 on the top section on the upper right side of the drawing. Below the
document feed tray 108 is arranged a document discharge tray 110, for
accommodating the stacked documents P after the document have been read. A
document feeder 114 is positioned on the document feeding end of the
document feed tray 108, i.e., at the end of the tray 108 in the document
feeding direction indicated by the arrow 112, for feeding the documents
stacked in the document feed tray 108 sheet-by-sheet.
The document feeder 114 is provided with a rotatable document take-up
roller 116 for feeding the document and disposed in contact with the
document P at the uppermost position of the stack of documents P placed on
the document feed tray 108. On the downstream side of the document take-up
roller 116 in the document transport direction is provided a pad 118
disposed adjacent to the take-up roller 116 for preventing a plurality of
sheets of the documents from being simultaneously taken up. On the
downstream side of the roller 116 in the document transport direction is
provided a U-turn path 122 for guiding the document P to the platen 104.
Within the path 122 is arranged a timing roller 124 for regulating the
document feed timing to the platen 104.
The document transport device 100 is provided with a manual document feed
tray 126 on the path 122 side. The manual feed tray 126 normally is
accommodated in a cavity formed in the housing 106, and is closed. The
manual feed tray 126 is opened at a position indicated by the hypothetical
line as necessary, and a document is manually inserted along the opened
manual feed tray 126 and is transported to the platen 104.
Above the platen 104 and below the document discharge tray 110 is
positioned a document transporting unit 128 capable of transporting a
document P along the platen 104. The document transporting unit 128
comprises rollers 130 and 132 positioned at bilateral ends of the document
transporting unit 128, and an endless belt 134 rove around the rollers 130
and 132. A plurality of rollers 136 are arranged medially to the rollers
130 and 132, and these rollers 136 press the belt 134 against the platen
104. A document P is gripped between the belt 134 and the platen 104 and
is transported by thew operation of the belt 134.
A U-turn path 138 is provided on the opposite side of the document feeder
114 and between the document transport unit 128 so as to eject a read
document P to the document discharge tray 110 provided above the document
transport unit 128. A pair of feed rollers 140, a large-diameter inverting
roller 142, a roller 144 in contact with the inverting roller 142, and a
pair of discharge rollers 146 are arranged between the document transport
unit 128 and the document discharge tray 110 along the path 138, so as to
guide a document P fed from the platen 104 into the discharge tray 110
along the path 138.
Provided on the opposite side from the path 138 and between the inverting
roller 142 are a re-feeding path 148 for inverting front-to-back the
document P and re-feeding the document to the platen 104, and a document
inverting unit 150 for inverting a document P front-to-back and
subsequently ejecting the document to the document discharge tray 110. The
document inverting unit 150 comprises a bottom guide 152 and a top guide
154 extending between the document discharge tray 110 and the document
transport unit 128, and a pair of feed rollers 156 for feeding/receiving
the document P between the guide rollers 152 and 154.
A first separation member 158 which is retractable relative to the path 138
is provided on the side of the path 138 for receiving a document P
transported along the path 138 and directing the document to the
re-feeding path 148 or the document inverting unit 150. The separation
member 158 is movable between the solid line position and the imaginary
line position, and directs a document P transported along the path 138 to
the document discharge tray 110 when set at the imaginary line position.
The separation member 158 directs a document P to the re-feeding path 148
or to the document inverting unit 150 when set at the solid line position.
A second separation member 160 is provided on the inverting roller 142 side
for directing a document directed by the separation member 158 positioned
at the solid line position to either the re-feeding path 148 or the
document inverting unit 150. The separation member 160 is movable between
the solid line position and the imaginary line position, and directs a
document P to the re-feeding path 1458 when set at the imaginary line
position. The separation member 160 directs a document P to the document
inverting unit 150 when set at the solid line position.
One end of the top guide 154 of the document inverting unit 150 extends
between the inverting roller 142 and the pair of discharge rollers 146, so
as to form a path 166 between the extended part 162 and the opposed guide
164. A pair of rollers 168 are arranged at the path 166 to transport a
document from the document inverting unit 150 to the document discharge
tray 110.
The document transporting operation of the document transport device 100
having the aforesaid construction is described below. A document P is
placed on the document feed tray 108, as shown in the drawing. At this
time, in the case of one-sided documents, the document surface is placed
facing upward, whereas in the case of duplex documents, the document
surface to be read first is placed facing upward. That is, in the case of
both one-sided documents and duplex documents the documents are stacked in
page sequence with the first page facing upward on the document feed tray
108. In this state, when a document feed command is output from the image
processing apparatus to the document transport device, the document
take-up roller 116 contacts the top surface of the uppermost document P,
and feeds the uppermost document P to the right side in the drawing. At
this time, the sheets below the uppermost document P is also fed to the
right side in the drawing due to friction between this sheet and the
uppermost document P. However, the sheets below the uppermost document P
are separated from the uppermost document P between the roller 118 and the
pad 120, so as to prevent their being fed. The document P which passes
between the roller 118 and the pad 120 is directed into the path 122 and
transported toward the platen 104 via the timing roller 124 and the timing
of the reading signals.
When the leading edge of the document P reaches the top surfaced of the
platen 104, the document P is transported in the arrow 170 direction along
the top surface of the platen 104 via the rotation of the belt 134 of the
document transport unit 128. When the document P has been transported to a
predetermined reading position, the document p is stopped until the image
reading is completed by the image processing apparatus 102. Then, when the
image reading is completed, the document P is transported from the top of
the platen 104 to the path 138 via the rotation of the belt 134.
When only one sheet of a one-sided document is placed on the document feed
tray 108, the one-sided document P is ejected to the discharge tray 110
regardless of whether or not the front or back surface is facing upward,
and poses not problem for the operator. In this instance, the first
separation member 158 is moved to the imaginary line position, and the
document P is transported by the roller pair 140, inverting roller 142,
roller 144 abutting the inverting roller, and the discharge roller pair
146, and is ejected to the discharge tray 110 with the document surface
facing upward.
When a plurality of documents P are stacked in the document feed tray 108,
it is desirable that the page sequence of the documents P is maintained in
the discharged state on the discharge tray 110. In the case of a plurality
of documents, the first separation member 158 is moved to the solid line
position. When reading only one side of a document P, the second
separation member 160 is moved to the solid line position. As a result, a
document P fed through the path 138 is transported to the document
inverting unit 150 via the pair of feed rollers 140, inverting roller 142,
roller 144, and feed roller pair 156. At this time the document surface is
facing upward.
Then, when the trailing edge of the document P arrives directly anterior to
the transport roller 156, the transport roller 156 temporarily stops and
rotates in the reverse direction. In this way the trailing edge of the
document P is fed into the path 166, and the read document is ejected to
the discharge tray 110 with the document surface facing downward via the
transport roller pair 168 and the discharge roller pair 146. The second
and subsequent documents are similarly fed, and stacked in the document
discharge tray 110 with the document surface facing downward.
When reading a duplex document, first the first separation member 158 is
moved to the solid line position and the second separation member 160 is
moved to the imaginary line position. In this way a document P fed through
the path 138 is again transported onto the platen 104 via the re-feeding
path 148. At this time the belt 134 reverse rotates to transport the
document P in the arrow 172 direction. After the image is read, the
document P is again fed into the path 138, and thereafter ejected to the
discharge tray 110 with the initially read document surface facing
downward without being transported to the document inverting unit 150
because the first separation member 148 has been switched immediately
beforehand to the imaginary line position.
In the previously described embodiment, the documents P are stacked on the
document feed tray 108 with the document surface to be read first facing
upward when reading a plurality of documents, but when the document
surface to be read first is placed facing downward, the document fed from
the document feed tray 108 must be inverted front-to-back twice so that
the document surface to be read is fed facing downward onto the platen
104. In this case, a pre-reading document inverting unit similar to the
document inverting unit 150 may be provided between the document feed tray
108 and the platen 104 so as to invert a document front-to-back once when
transporting documents from the document feed tray 108 to the document
inverting unit, then inverting the document front-to-back once again when
transporting the document from the document inverting unit to the platen
104. In this instance, the feed rollers are arranged below the document so
as to contact the lowermost document stacked in the document feed tray
108.
In the document transport device of the present invention as described
above, since a document feed tray, document discharge tray, and document
inverting unit are provided above the platen of the document reading unit,
the width of the document transport device in the lateral direction in
FIG. 3 can be suppressed to the width of the image processing apparatus.
Furthermore, because a plurality of documents are read in the page
sequence, a compact facsimile machine or scanner can be realized.
In the aforesaid document transport device, consideration has been given to
the use of the document re-feeding path 148 to direct a read document from
the re-feeding path 148 onto the platen 104, and thereafter eject the
document from the trailing edge to the document discharge tray 110. In
this case, the ejected documents are stacked on the discharge tray 110
with the read document surfaces facing downward. However, in this
arrangement the total document reading time is disadvantageously
lengthened because the following document must be awaited to prevent
interference impact between a document returning to the platen 104 and a
following document transported to the platen 104. Accordingly, a read
document is directed to the special document inverting unit 150 as
previously described. In this way a document on the platen 104 is not
interfered with. If the document reading is completed, a following
document can be immediately directed onto the platen 104, thereby reducing
the document reading time.
Although the document feed tray 108, document discharge tray 110 and the
document inverting unit 150 are sequentially arranged vertically from the
top down in the aforesaid document transport device, the arrangement
sequence of the pre-reading document inverting unit is not limited to the
aforesaid embodiment, and may be combined in a vertical relationship.
Although a specific construction of the first mode of FIG. 1 is shown in
FIG. 3, the document transport device of the mode shown in FIG. 2 may be
realized via modification of the construction shown in FIG. 3.
Specifically, the feed roller 116 may be arranged so as to contact from
below the lowermost document surface of the documents stacked on the
document feed tray 108, so as to oppose the positional relationship of the
roller 118 and the pad 120. In this way documents stacked on the document
feed tray 108 are fed sequentially sheet-by-sheet from the bottom.
Furthermore, a tray may be added between the document feed tray 108 and
the document transporting unit 128, and a feed roller capable of reverse
and forward rotation may be provided between the added tray and the path
122. A document is transported from the path 122 onto the added tray via
the standard rotation of the feed roller, and a document is fed from the
added tray to the path 122 and the transport unit 128 via the reverse
rotation of the feed roller.
Although the present invention has been fully described by way of examples
with reference to the accompanying drawings, it is to be noted that
various changes and modification will be apparent to those skilled in the
art. Therefore, unless otherwise such changes and modifications depart
from the scope of the present invention, they should be construed as being
included therein.
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